Chair

ABSTRACT

A chair seat which is connected to a support leg through connecting means and free to be moved backwardly and rotated about said support leg and designed for automatic restoration to its former position, which is characterized in that an elongated resilient means acting linearly between the seat and the connecting means operates to control the backward movement of the seat and another elongated resilient means which is adapted to act angularly between the connecting means and the support leg operates to control the rotation of the seat.

United States Patent [191 11] 3,705,700 Kubo Jan. 15, R974 [54] CHAIR1,903,267 3/1933 Roberts 248/417 2,409,114 l0/l946' Elleman et al..248/417 UX [75] Invent sh'mhel Kulm Japan 3,637,185 1/1972 Mikos et al.248/417 [73] Assignee: Kabushiki-Kaisha Kubo Shoten,

Tokyo, Japa Primary Examiner-Paul R. Gilliam [22] Filed: Feb. 29, 1972Attorney-Schlesinger, Fitzsimmons & Schlesinger 7 [2!] Appl. No.:230,256

[57] ABSTRACT [30] F i A li ti P i it D t A chair seat which isconnected to a support leg Mar. 26 1971 Japan 46/17772 thmugh cmmwngmeans and free be "mved back wardly and rotated about said support legand de- [52] US Cl 297/349 297/383 108/140 signed for automaticrestoration to its former position, 248/417 which is characterized inthat an elongated resilient 51 int. Cl. B60n 1/02, Fl6m 13/00 meansacting nearly between the S and the [58] Field of Search 297/349 383'wing means Operates the backward 248/417425. g movement of the seat andanother elongated resilient means which is adapted to act angularlybetween the [56] References Cited connecting means and the support legoperates to con- UNITED STATES PATENTS trol the rotation of the seat.

2,755,842 7/1956 Caramelli 248/417 UX 2 Claims, 7 Drawing FiguresPAIENHUJANISBM 7 3 785 700 SHEET l} UF I CHAIR This invention relates toa chair which can be moved backwardly with respect to its support leg orrevolved about its support leg and returned to its former positionautomatically and without the necessity of any particular manipulation.Backward movement and revolution of the chair can be obtained when aperson seated on this chair applies his foot pressure to the floorsurface or twists his body. Thus, a person seated on this chair can takeanything around and behind him without any particular effort, or have achat with others behind him.

A preferred embodiment of this invention will be explained in detailhereinbelow by referring to the accompanying drawings, in which:

FIG. 1 is a side elevation of a chair according to the presentinvention;

FIG. 2 is a plan view thereof, in which a part of seat is cut out;

FIG. 3 is a partially broken bottom view of substantial mechanical partsthereof;

FIG. 4 is a cross section taken on the line IV IV of FIG. 3;

FIG. 5 is a cross section taken on the line V V of FIG. 3 and shown withits frame plate removed from FIG. 3;

FIG. 6 is an enlarged longitudinal sectional view of substantial partsillustrated in FIG. 5; and

FIG. 7 is an enlarged bottom view of substantial parts of the chair,shown in FIG. 3.

A generally denotes a seat for a sofa-like chair having a chassis 6fixed to its underside. A movable frame 2 rectangular form is fixedlyaccommodated within the chassis 6, so as to open towards the underside.The longitudinal sides of the guideframe 2 are formed with guide rails20, 2b having both upper and lower rail faces. On either sides of asupport I housed within said movable frame 2, there are provided threewheels 3 for rolling on the upper rail faces of the guide rails 2a, 2b.Peripheral lugs 7a (FIG. 6) of a circular support plate 7 are secured tothe inner upper surface of the support 1. Ball grooves 9 are formed onsaid support plate 7 on the circumference of a circle concentrictherewith and so as to open towards the underside.

A support leg B for the chair has a support plate 10 (FIG. 1) at itslower end and a top part 4 to which a plate 5 having a substantiallysimilar shape to said circular support plate 7 is secured at its lugparts 5a by bolts 8'. Ball grooves 11 are formed on said plate 5 on thecircumference of a circle concentric therewith and so as to open towardsthe upper side. Six balls or rollers D fitted into retainers 12 areinserted for free rolling motion into spherical recesses defined by saidball grooves 9 on said support plate 7 and said ball grooves 11 on saidplate 5. A bolt 13 is mounted to said support 1 as a center shaft forsaid circular support plate 7 and said plate 5. A nut 13 is threaded tosaid bolt 13 from the lower side of the plate 5.

C, C (FIG. 3) denote cables having sufficient elasticity and engaging attheir both ends C1, C2 to a front plate la of the support 1 and a rearplate 2c of the frame 2 which is fixed to the seat A through the chassis6 and movable with respect to the chair leg B being guided by thesupport 1 through the wheels 3. A further cable C having likewise asufficient elasticity is engaged at both ends to the front plate 1a ofthe support 1, said cable C is coiled around circular grooves 14 (FIG.6) formed on the outer circumferential surface of the plates 7 and 5 andsecured at its center to the outer surface of the plate 5 by mountingmembers 15 (FIGS. 3 and 7). l6 denotes a rubber stopper.

It should be noted that the cables C, C could each be a single cable ormore than two. Though in the embodiment illustrated in the drawing andexplained above with reference to the drawing, the cable C is acontinuous single piece encircling around the circular grooves 14 andfixed at its both ends to the support 1, it should be noted also thatsaid cable C could consist of a pair of cables of equal length eachhaving one end fixed to the support 1 and another end fixed to the plate5 independently of the other cable after partially encircling thegrooves 14.

When a person seated on the seat A having the above-mentionedconstruction and, with the support leg B firmly placed on the floor,applies his foot pressure on the floor surface, for urging the chairseat A to be moved backward in the direction indicated by the arrow mark(X) (FIG. 2), the chair seat A is moved in said direction. Moreparticularly, the movable frame 2 is moved, along with chair seat A andchassis 6, in the direction of the arrow mark (X) against the resiliencyof the cables C, C, the rollers 3, 3 then rolling on the guide rails 2a,212 formed on the movable frame 2 so as to make the backward movement ofthe movable frame smooth. When the force acting in the direction of thearrow mark (X), that is, foot pressure applied on the floor surface, isreleased, the movable frame 2 will be moved, together with chair seat Aand chassis 6, back to its former position or in a direction reverse tothat shown by the arrow mark (X), under the recoiling force of thecables C, C.

When a person seated on the chair twists his body for partial rotationof the chair seat A in the direction shown by the arrow mark (Y) (FIG.7), in either direction, the support 1 along with the plate 7 and themovable frame 2 will be revolved partially as a unit. It will berealized readily that a smooth revolution of the moving members isenabled at this time-because of balls D (FIG. 6) interposed between thestationary plate 5 and the circular support plate 7 which is forced intorevolution concurrently with chair seat A, one of the cables C issubjected at this time to a tractive effort and elongated resiliently,while the remaining one C' is idle and out of operation. When therotatory effort applied to the chair seat is released, the chair seat Awill in a reverse direction, under the recoiling force of the cable C,and be restored to its former position.

When both rotatory and backward effort are applied to the chair seat A,in an intention to rotate and move it backward concurrently, both thecables C, C are elongated simultaneously, with the result that theclastic recoiling force is accumulated in said cables C, C. Thus, uponreleasing the effort applied to chair seat A, the latter will bereturned to its former position, the for ward movement and reverserotation of the chair seat A then taking place concurrently. In thepresent embodiment of the invention, cables composed of strands ofrubber and fiber etc. with sufficient strength and resiliency are usedfor producing resilient tractive force, but they can also be replaced bycoil springs, other elastic filaments or other elongated resilient meanswithout departing from the scope of the invention.

According to the present invention, as above described, the movableframe 2 for chair seat A in the form of a rectangular frame movablysupported by support 1 therein is free to slide linearly backwardsthrough a plurality of rollers 3, since at least one cable C withsufficient resiliency connects said support 1 and movable frame 2. Onthe other hand, the plate 5 secured to the upper part 5 of the supportleg B is stationary relative to said support 1 which is rotatable withrespect to the leg B through rollers D, since at least one cable C withsufficient resiliency works between said plate 5 and support 1. Thus,when desired to move the chair seat A, a light sliding movement will bebrought about by virtue of rollers 3 interposed between the support 1and the movable frame 2. The chair seat A thus moved backward can bereturned to its former position smoothly and automatically under therecoiling force of the cable C which has been elongated with thebackward movement of the chair seat A. Further, the chair seat Arevolved partially can be restored to its former position smoothly andsimultaneously under the recoil force of the cable C. In addition, thechair seat A can be revolved partially at the same time that it is movedbackward and the chair seat A can be returned to its former positionunder simultaneous operation of the cables C, C. The construction of thepresent chair is highly simplified by virtue of provision of theresilient cables C, C.

In execution of the present invention, a plurality of cables C can alsobe utilized, while the cables C can be secured to any other positionsthan those specified in the present embodiment, at the manufacturersoption.

What is claimed is: 1. A chair in which the seat is free to besimultaneously moved linearly backwardly from a forward position of restand rotated about its support leg, and designed for automaticrestoration to its rest position, comprising a movable frame member forthe chair seat in the form of a rectangular frame,

a support member slidably fitted in said frame,

a plurality of rollers slidably supporting said frame member in a fixedplane on said support member,

at least one resilient cable placed intermediate said support member andsaid movable frame member and constantly urging said frame memberlinearly to rest position,

a plate secured to the upper part of the support leg,

means mounting said support member on said plate to rotate about theaxis of said leg, and

at least one other resilient cable placed intermediate said plate andsaid support member and constantly urging said support member angularlyabout said axis to an angular rest position.

2. A swivel chair, comprising a seat,

a stationary leg,

an elongate frame member fixed to the underside of said seat,

a first support member fixed on said leg,

a second support member rotatably mounted on said first support memberand secured against axial movement relative thereto,

means slidably mounting said frame member on said second support memberfor rotation therewith and for longitudinal reciprocation thereon in afixed plane that extends transverse to said leg,

first elongate resilient means normally biasing said frame memberforwardly to a first limit position on said second support member, andpermitting said frame member to be slid rearwardly on said secondsupport member upon exertion of a backward force through said seat tosaid frame member, and

second elongate resilient means connecting said second support member tosaid leg and normally resiliently resisting the rotation of thelast-named member out of a position of rest on said first supportmember, and permitting rotation of said lastnamed member upon executionthereon of a turning moment through said seat,

said mounting means including means permitting simultaneous linearmovement of said frame member and angular movement of said secondsupport, I

wherein said support member comprises a pair of circular plates having aplurality of ball bearings interposed therebetween, and

said second resilient means comprises a resilient cable seatedintermediate its ends in a circumferential groove formed between theconfronting, marginal peripheral surfaces of said plates, and fastenedat opposite ends to one of said plates and intermediate its ends to theother of said plates.

1. A chair in which the seat is free to be simultaneously moved linearlybackwardly from a forward position of rest and rotated about its supportleg, and designed for automatic restoration to its rest position,comprising a movable frame member for the chair seat in the form of arectangular frame, a support member slidably fitted in said frame, aplurality of rollers slidably supporting said frame member in a fixedplane on said support member, at least one resilient cable placedintermediate said support member and said movable frame member andconstantly urging said frame member linearly to rest position, a platesecured to the upper part of the support leg, means mounting saidsupport member on said plate to rotate about the axis of said leg, andat least one other resilient cable placed intermediate said plate andsaid support member and constantly urging said support member angularlyabout said axis to an angular rest position.
 2. A swivel chair,comprising a seat, a stationary leg, an elongate frame member fixed tothe underside of said seat, a first support member fixed on said leg, asecond support member rotatably mounted on said first support member andsecured against axial movement relative thereto, means slidably mountingsaid frame member on said second support member for rotation therewithand for longitudinal reciprocation thereon in a fixed plane that extendstransverse to said leg, first elongate resilient means normally biasingsaid frame member forwardly to a first limit position on said secondsupport member, and permitting said frame member to be slid rearwardlyon said second support member upon exertion of a backward force throughsaid seat to said frame member, and second elongate resilient meansconnecting said second support member to said leg and normallyresiliently resisting the rotation of the last-named member out of aposition of rest on said first support member, and permitting rotationof said last-named member upon execution thereon of a turning momentthrough said seat, said mounting means including mEans permittingsimultaneous linear movement of said frame member and angular movementof said second support, wherein said support member comprises a pair ofcircular plates having a plurality of ball bearings interposedtherebetween, and said second resilient means comprises a resilientcable seated intermediate its ends in a circumferential groove formedbetween the confronting, marginal peripheral surfaces of said plates,and fastened at opposite ends to one of said plates and intermediate itsends to the other of said plates.